Radomaniola mislinensis Grego et Jaszczyńska sp. nov.

Zoobank number: urn:lsid:zoobank.org:act: D2A9D710-6119-4777-BDBD-FB210D35ED6C

GenBank sequence numbers: PX113142–PX113146

mOTU B

Type locality CROATIA • Splitsko-Dalmatinska županja, Metković distr., Neretva River Delta, Mislina, Mislina spring (locality 14: Figs 1 and 2E, H); 42°58’56”N; 17°36’24”E; 4 m a.s.l.; at the bottom of spring head at the bank of spring lake under the road.

Holotype CROATIA • ethanol-fixed specimen (Fig. 11A), Mislina spring, Mislina, delta of Neretva River, District Metković, Splitsko-Dalmatinska županja, Croatia (locality 14: Figs 1 and 2E, H); 42°58’56”N; 17°36’24”E; 04.08.2020; Andrzej Falniowski, Roman Ozimec and Jozef Grego legs.; NHMW-MO-113906.

Paratypes CROATIA • 96 dry and 78 ethanol-fixed specimens; type locality; data as for holotype; 39 ethanol-fixed specimens in ZMUJ/2024/03; 5 dry specimens NHMW-MO-113907; 91 dry and 46 ethanol-fixed JG F2583; CROATIA • 38 dry and 72 ethanol-fixed specimens, from type locality, 27.07.2024, Roman Ozimec and Jozef Grego legs., 10 dry and 10 ethanol-fixed specimens in GMV 112631, 28 dry and 55 ethanol-fixes specimens in JG F3769.

Description Shell (Fig. 11A–D) up to 2.27 mm high, ovate-conical, broad, with spire low or moderately low, with about five whorls, spire height 20–24% of the shell height. Teleoconch whorls slightly convex, evenly rounded, growing regularly and slowly in diameter, penultimate whorl disproportionally low in some specimens. Aperture moderately narrow and ovoid, outer lip simple, parietal lip complete or not, moderately broad, umbilicus slit-like. Teleoconch moderately thick-walled, its wall translucent, growth lines delicate or more visible, periostracum whitish or yellowish. Shell measurements: Table 3, Fig. 15. Protoconch (Fig. 11E) growing slowly, no sharp border between proto- and teleoconch, its micro sculpture delicate and irregular. Operculum yellowish-brownish, smooth on both surfaces.

Soft parts morphology and anatomy Head, mantle and visceral sac intensely pigmented black. Female reproductive organs unknown. Penis (Fig. 11F–G) long, narrow and bent, proximally broad and ellipsoid in shape, distally sharp, on the left side of the penis is a single narrow and sharp outgrowth, vas deferens visible inside the penis.

Differential diagnosis From the most closely related species— R. torifera and R. testavariabilis sp. nov. — it differs in its penis having a single, finger-shaped sharply pointed outgrowth. The Molecular Diagnostic Characters in comparison with all Radomaniola sequences used in phylogenetic analysis: binary 342(G). In comparison with other new Radomaniola species: binary: 96(C), 342(G), 360(T), 372(G), asymmetric: 390(C). In comparison with R. testavariabilis sp. nov. and R. torifera: binary: 96(C), 342(G), 360(T), 372(G), 390(C).

Etymology The name reflects Mislina spring, its type locality.

Distribution and habitat Apart from type locality, found also at spring Studena, locality 13 (Fig. 1, Table 1).

Ecological status The AOO and EOO are represented by a spring supplying a small lake Mislina at N edge of swamps adjacent to Kuti Lake and by adjacent parts of the small lake, in area about 50 m 2. Locality in Neretva Delta is dependent upon a supply of fresh spring water and is threatened by climatic changes and declining of the spring water outlet causing eutrophication. Additionally, locality is endangered by anthropogenic pollution by municipal or chemical waste from local settlement and adjacent road, as well as by anthropogenic alternations of the springs by construction activities. Locality in Studena is a small fountain close to a road and heavily affected by road construction and excavation work. Therefore, it is assessed as Endangered (En).